Author + information
- Masayasu Ikutomi1,
- Kozo Okada1,
- Kojiro Miki2,
- Ryo Kameda1,
- Fumiyuki Otsuka3,
- Paul G. Yock1,
- Peter J. Fitzgerald1,
- Osami Kawarada4 and
- Yasuhiro Honda1
- 1Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, California, United States
- 2College of Hyogo Medcine, Kobe, California, United States
- 3National Cerebral and Cardiovascular Center, Osaka, Japan
- 4Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center, Osaka, Japan
Sustained enlargement force of self-expanding stents may cause chronic arterial injury, which can contribute to neointimal hyperplasia (NIH) after stenting. This study aimed to examine the temporal and spatial differences in chronic stent enlargement, as well as their effects on subsequent development of NIH, among 3 new generation self-expanding nitinol stents implanted in tapered arteries assessed by serial optical coherence tomography (OCT).
Misago, SMART Flex, or Innova (n=6 for each, 6 x 60 mm) was randomly implanted in healthy swine models from distal superficial femoral to proximal popliteal artery with no pre/post-dilation. Volumetric OCT was performed at baseline, post-stent, 4 weeks, and 13 weeks analyzed at every 5 mm through the stented segment.
At post-stent, both the degree and axial geometry of acute stent expansion were comparable among the 3 stents (P=0.40 and P=0.88, respectively). While all stents showed late enlargement during follow-up, the 3 stent types showed significant differences in temporal change (P=0.0036) and spatial distribution (P=0.028 at 4 weeks, P<0.0001 at 13 weeks) of stent expansion (Figure). Overall, the degree of late stent enlargement significantly correlated with NIH at 13 weeks (R2=0.235, p<0.001). Consequently, axial NIH distribution at 13 weeks significantly differed among the 3 stent types (P<0.0001); Misago showed the lowest degree of NIH particularly at the distal stent edge where the least degree of late stent enlargement was observed among the 3 stents.
The 3 new generation self-expanding stents showed considerable differences in the time course and axial geometry of late stent enlargement and subsequent NIH. Misago appeared to most accommodate the tapered artery, possibly leading to reduced arterial injury particularly at the distal stent segment.
ENDOVASCULAR: Peripheral Vascular Disease and Intervention